DESCRIPTION (Applicant's Description Verbatim): Anticoagulation of blood is necessary for prevention of clotting and/or thromboembolism during extracorporeal circulation. Conventionally, anticoagulation is achieved by administering heparin and reversed by neutralizing with protamine. Both of these procedures may have potential pathological consequences. The applicants have conceived an approach that will obviate the need for heparin as well as protamine. They have developed a clotting factor filter, and through in-vitro studies, demonstrated that it is possible to reversibly bind to a solid substrate certain key clotting factors (prothrombin complex) and thus remove those factors from circulating blood. This renders the blood hypocoagulable. They have also worked out a strategy to harvest the bound clotting factors and return these autologous factors to the blood, thereby restoring its clotting function. This is a proposal to explore the possibility of using the clotting factor filter in an ex-vivo configuration, and thus test the feasibility of: i) rendering the circulating blood hypocoagulable in vivo and ii) establishing that bound clotting factors can be safely returned to the circulating blood in vivo. Success of the proposed experiments will lead to the development of a clotting factor filter for clinical application. PROPOSED COMMERCIAL APPLICATIONS: The proposed research will lead to the development of a simple device that may present an alternative to the current coagulation management with heparin for extracorporeal circulation. This device will obviate the need for both heparin and protamine.